Amplifier problems

I have a Kenwood MC-7201 amp (US is KAC-7201). It worked great for four months and then the main fuse which is inline off my battery blew. I screwed around with that for a month until I found a new ground point. The amp now powers up and doesn't blow the inline fuse, but as soon as my deck kicks in the two 30 amp fuses on the amp itself blow. Electronics aren't my specialty, but can someone tell me what the hell is going on.

sounds like you probably have a bad amp. i would open it up if it isn't under warrenty any more and see if you have any visual cues (like a burned spot on a board or some melted resistors and the such) if it is on warrenty i would take it in and say wtf!!!

if you don't have a warranty try using some bigger fuses. i mean if its already broken you don't have to worry about breaking it.

mobomelter said:

if you don't have a warranty try using some bigger fuses. i mean if its already broken you don't have to worry about breaking it.

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I'd definately would not do that. If you are blowing the fuses you have a electrical issues and need to address them the right way instead of just adding fuel to the fire.

Fuses on an amp blow for 2 reasons, the amp is smoked or the speaker wires are shorting out.

Check your speaker wires.

i mean thats what i would do personally. if they blew again then i would check it out.

The fuses are blowing for a reason, and it is not because the amp is too powerful. There is something wrong witht the system.

Thanks for the help thus far. If I blew like 3 main fuses off the battery while I was trying to figure things out would this effect the amp. I heard there was a safety switch that wears out if you abuse your amp too much. Right now I think it might be the speaker wires, because the amp powers up and looks fine until the deck kicks in. I am just worried that this is something major that if I get a new amp (i still got a month of warranty) that I will just be in the same boat.

you should cash in on the warranty while you still have it. at least if you get a new amp from the warranty you have elimintaed any possibility of the amp being the problem.

saskmazdaman11 said:

Thanks for the help thus far. If I blew like 3 main fuses off the battery while I was trying to figure things out would this effect the amp. I heard there was a safety switch that wears out if you abuse your amp too much. Right now I think it might be the speaker wires, because the amp powers up and looks fine until the deck kicks in. I am just worried that this is something major that if I get a new amp (i still got a month of warranty) that I will just be in the same boat.

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Depends on the amps quality. I have seen kenwood amps that never go into protection, they just nuke. I had an Xtant that didn't even go into protection and it didn't get damaged, it just didn't work until I fixed the problem and my JLs will go immediatly into protection, they won't blow fuses.

If you blew a fuse at teh battery for the amplifer while installing, then something was wrong then. Typicly that means the power wire is grounding somewhere. This can smoke the amp if you had the power wire connected to it incorreclty. I have certainly seen it happen.

What is the state of things now?
It sounds like the fuse on the power wire is ok but its the fuses on the amp that keep blowing?
What did you change to get the fuse on the power wire to stop blowing?

I would disconnect the speaker wires from the amp, and then find any speaker just laying around (home audio is fine) connect that the amp temporarily just to be sure it powers up and plays ok. If it does, you know its something in the wiring or the speakers/sub you have connected that is the issue. I have seen this happen sometimes when a speaker self destructs and becomes an almost zero ohm load, essentaily shorting out the speaker wires. So once you make sure the amp is ok, try to use the speaker on another amp and make sure its good.

I guess my amp is fubared. Over the weekend I worked on it and it still isn't working. I got the amp to power up but it torches the fuses on the amp as soon as the deck kicks in. I unhooked the RCAs and speakers and just left the power, ground, and control. So I guess I have to go hunting for my receipt and bring it in somewhere. Thanks for the help.

Yep, I'd have to call it FUBAR